The sympathetic block procedure entails blocking the transmission of pain signals from sympathetic nerve roots as a means of treating persistent pain. This type of block is typically performed if conventional treatment methods such as over-the-counter pain medication or steroid injections have not been effective at relieving persistent pain. It may also be suggested if serious side effects developed due to conventional methods.

The roots of sympathetic nerves are located in the spinal cord, but the nerve fibers extend to all major parts of the body such as the extremities, muscles, glands, and organs (e.g., heart). The primary function of these nerves involves the transmission of sensory information such as pain, touch, or temperature and they also regulate numerous processes including respiration, heart rate, perspiration, facial and body movement, and digestion.

Sympathetic nerve blocks have proven to be effective at treating numerous types of persistent pain in different regions of the body, but most commonly in the back, neck, head, the upper or lower limbs, and the tailbone. Accurately pinpointing the location that is causing the pain is essential in treating the appropriate sympathetic nerves and relieving the pain.

How Is A Sympathetic Block Performed?

The procedure for a sympathetic block involves the insertion of a needle through the tissue and into the region where the targeted sympathetic nerves have been located. An imaging technique such as fluoroscopy is used during the placement of the needle and a catheter is inserted through the needle as well. To further ensure the proper insertion of the needle, a contrast dye is injected before the medication is administered. After confirming the correct placement, anesthesia or a chemical agent that causes nerve tissue to disintegrate, is delivered to the nerve roots.

The needle is usually inserted through one of the following approaches: anteriorly, transdiscally, or posteriorly. The anterior approach refers to having the patient lie on the back during the needle insertion, whereas the patient will lie on the side when the needle is transdiscally inserted. When the needle is inserted posteriorly, the patient lies on the stomach so the needle can be placed into the region below the spine that is directly above the buttocks. The posterior method is most frequently performed because it poses the lowest occurrence of injuries to the nerves, veins, arteries, and spinal discs.

During this procedure, there is a risk of puncturing arteries, veins, spinal discs, and nerves, but the use of imaging technology to insert the needle minimizes these risks. Fluoroscopy, an ultrasound, X-ray, or computed tomography (CT) may be used for the imaging process. CT scans are not commonly used because both the patient and surgeon become exposed to high radiation levels.

Conditions Related To Sympathetic Blocks

Sympathetic blocks have proven to be effective at treating various conditions, which include:

Pain in the body (e.g., back, head, neck, tailbone, extremities)

Complex regional pain syndrome

Pain associated with cancer

Neuropathic pain due to tissue or nerve damage

If bodily pain was repeatedly treated with anti-inflammatory medicine, steroid injections, or pain medication, but these methods were ineffective, a sympathetic block is often suggested. Many patients report that this treatment approach dramatically decreases or alleviates their pain. In addition, some patients no longer need any form of pain medication.

Complex regional pain syndrome is a painful condition that is described as experiencing intense pain that is not proportionate to the event that led to it. Patients with this condition typically feel pain in an arm or leg after undergoing surgery, having a stroke or heart attack, or after an injury. Accurately determining the cause of this condition can be very hard for a clinician and this makes treating this syndrome difficult as well. Nerve damage is suspected in most cases and if pain dramatically decreases after undergoing a sympathetic block, it provides evidence that impaired nerves were causing the pain.

Cancer patients whose pain is not effectively treated with antidepressants, non-steroidal anti-inflammatory medicine, or pain relievers, generally report dramatic pain relief after undergoing a sympathetic block. A number of patients are also able to take less of their prescription medication as well.

Sympathetic nerves blocks are also commonly used for the treatment of brown recluse spider bites, which can cause nerve damage, tissue inflammation, and neuropathic pain. When the block technique is performed with an anesthetic, pain greatly decreases and tissue repair improves.

In general, the sympathetic block technique is minimally invasive and can be performed quickly. The majority of patients who receive this type of injection report significant improvement that persists for several months. The block is a highly effective treatment approach because it allows specific nerves that are contributing to the pain to be targeted.

Conclusion

A sympathetic block is a treatment method that is used for different types of pain. It involves blocking the transmission of pain signals from sympathetic nerves that are causing a patient’s pain. By blocking the transmission of sympathetic nerve signals, this technique has proven to be effective at providing pain relief, especially if other forms of treatment (e.g., pain relievers, injections) were ineffective or caused adverse side effects. Patients often report significant and long-term improvements in pain. In addition, a number of patients can discontinue their medication or take a lower dosage after receiving this type of treatment.